Influence of some factors on the epidemiology of leaf rust (Cerotelium fici) disease in mulberry (Morus alba L.)

Abstract

Foliar diseases cause substantial loss in the production and quality of mulberry foliage. Among the various foliar diseases, leaf rust caused by Cerotelium fici constitutes the greatest epidemiological constraint affecting almost all the popular mulberry cultivars cultivated in India. The present study was undertaken to understand the influence of various epidemiological factors on disease development in seven promising mulberry cultivars namely, Local, K2, S13, S34, S36, S54 and MR2 during summer, rainy and winter seasons for three consecutive years. Disease development and its progress were greatly influenced by crop age and weather factors such as maximum and minimum temperature, percentage of relative humidity, cumulative rainfall and total rainy days. Correlation and regression studies indicate that all the variables related to weather factors and crop age were significantly and positively correlated with disease initiation and its development. With increasing crop age, a significant increase in disease severity was recorded in all the mulberry cultivars. The relationship between the crop age and its influence on disease development was better explained by non-linear quadratic function i.e., Y = 0.003x2 + 0.004x − 1.60 and Y = 0.005x2 − 0.170x − 2.09 in rainy and winter seasons, respectively by showing coefficient determination (R2) more than 90% in each case.